Firing device for land mines



m 33' G. M. n1-A. FONTAINE 396.94m

FIRING EEVICE FOR LAND MINES Filed DBC. 19, 1938 nve nl'or.

rma nevica ron Nn l l Georges Marie Telesphore alexandre Fone, Paris, France; vested in the Alien Property Custodian application necemtari9, 193e, serai No. Marzo in France February 16, 1933 (Cl. 10ft-43) 9 Claims.

'l'his invention relates to improvements in or iodiflcations of the device for the protection of he ground of military operations by means of lines or other like appliances, described in the pecication of U. -S. Letters Patent No. ,128,839, in which the firing mechanism of each f the protective appliances is associated with pull or push member, such as a cable or other 'lire member, one of the ends of which produces .irectly or indirectly, for example by means of trip device, the movement of the movable riember of the firing mechanism, the device being haracterised in that it comprises a cable guided u a sheath constructed so as to-be capable of longating under the effect of a deformation, ne of the ends of one ofthe said elements cable or sheath) being fixed to the movable member of the ring mechanism or to a part etaining the said member, while the correspondng end of the other element (sheath or cable) s fixed to-or supported on the said appliance, he other two ends of the said associated elements being secured together or having, in a. econd appliance coupled to the first, the same Ielative dispositions or inverse dispositions as n the first appliance.

In the hereinbefore mentionedA specicatiod yhere are described in addition and shown by vayof example, different forms of construction if the invention, in which forms one of the :nds of the cable is fixed to the movable mem-5 Jer of the iring mechanism or to a part retainng, the said member, While the corresponding and of the sheath is fixed to or supported on '.he appliance itself. The elements forming the heath may have extremely varied forms.

@ne ci the presentimprovements relates to a particular form of construction of the invention lcscribed in the hereinbefore mentioned specifi- ;ation, and to a particular form of arrangingV which are disposed rings made of an` e'xtremely ductile metal, annealed aluminium for example,4

companying drawing, but these forms of construction may be modified in their details or may be completed by any suitable accessory device without departing from the invention.

Referring to the drawing,

Figure 1 shows a diametrical section of the ringdevice and of one of the elongation control groups of the sheath.

Figure 2 represents across-section on the line i II-II of Figure 1.

Figures 3 and 4 represent sections of two devices for the relative adjustment of the cable and its sheath by a take-up screw.

Figures 5 and 6 show two sections of a device for the relative adjustment of the cable and its sheath by means of a sort of wedge.

As will be seen in Figure 1, the form of construction according to the present invention comvprises as firing mechanism a fuse. the head I of which is screwed on the appliance 2 to be exploded and carries a xed percussion-cap 3 mounted in a likewise xed percussion-cap carrier il which is struck at the'moment of ring by a. striker E.

;he deformable :sheatheinployed for effecting In the form of construction under considera- The rlatter, which is normally xed by means of a pin 6, is subjected to the action of a thrust spring 1 bearing on a xed part 8 and also to the action of a sort of fork 9,' the armani-I0 of which'pass freely through suitable orices il provided in the flxed'part 8, against which is applied the end `I2 of the deformable external sheath I3 surrounding the retaining cable i4.

' The end It of the latter is secured in any suitable manner tothe xed part t and conse qufntly to the fusebdy i.

i hanged socket 16, for example, is employed for this purpose. A t Y The operation of the device is extremely simple to understand.

when, due to its being crashed at the mo: ment of `the passage of a tank, the sheath it undergoes elongation relatively to the constant ducing the ignition of the explosive charge.

In the upper part of Figure 1 is shown one of the different elongation control groups provided along the sheath.

The latter, which comprises in the vicinity of the fuse 'a flexible part il, also includes a series of beads i8, i9, etc., and, at spaced points, groups of four beads 2l) of large diameter having the form of biconvex lenses, between the edges of which are disposed rings 2| made, as stated hereinbefore, of an extremely ductile metal, such as, for example, annealed aluminium. As shown, the outer surfaces of the rings 2| extend beyond the peripheries of lenticular beads 2t) so that. when a tankor other heavy object passes over a portion of the sheath embodying one of the elongation control groups, the rings 2l will be crushed and portions thereof will be forced between and spread the beads 2t, thereby elongating the sheath and igniting the explosive charge in the manner above described.

The end 22 of the cable Ui has an expanded form which prevents it from entering the interior of the last bead 23 of the sheath.

If desired, a flexible sheath element 2t may be interposed between the bead 23 and the other beads of the sheath.

If it is desired to be able to adjust the length of one of the elements, cable or sheath, relatively to the other, so as to adjustat the same time the application of the end I2 of the sheath against the part 9, it is possible to employ one of the devicesshown respectively in Figures 3. 4, and 6.

In the forni of construction shown in Figure 3, there are provided, between the bead 22 and the flexible sheath element 2t, two adjacent beads 25 and 26, the first of which, the bead 2t', forms a sort of .internally screw-threaded sleeve, while the second, the bead 2t,- comprises a screwthreaded body 21 adapted to screw in the internal screw-thread of the bead 29'.

It is easy to understand that by screwing the bead 26 more or less in the bead 2d, the assemblage formed by these two members is given a greater or lesser length, the consequence of which is to increase or reduce, as desired, the total length of the sheath.

In the form of construction shown in Figure 4, the bead -26 is screwed directly in the end lenticular bead 20 of one of the crushing control groups, which lenticular bead is provided ior this purpose with an internal screw-thread 2t.

In the form of construction shown in Figures 5 and 6, of which the first is a section on the line V-V of Figure 6, while the second is a sectional plan of the part .of the mechanism situated below the plane VI-VI of Figure 5, thel adjustment of the length of the sheath relatively to that oi.' the cable ifi is effected by means of a key 2u having the form of a fork, the arms 3d of which act as forcing wedges between the end bead 23 and the preceding bead 3|.

1. In apparatus of the character described for protecting the ground of military operations asoaefai face of the ground, the sheath ol' said cable'belng so constructed and arranged as to elongate when deformed by the passage thereover of a tank or other heavy object and having its outer end fixed relatively to the outer end of said cable, the combination of means for securing the inner end of said cable to said explosive device, a firing mechanism mounted within said device having one element fixed relatively to the latter and another element movable relatively thereto, a spring tending to move said movable element into firing position, frangible means normally restraining said movable element from movement under the influence of said spring, and a second movable element housed within said explosive device in abutting relation with said first movable element, said second movable element being so constructed and arranged as to receive the inward thrust of the inner end of said cable sheath when the latter is elongated and to transmit said thrust to said rst movable element, whereby elongation oi said sheath may effect a fracture of said restraining means and permit said spring to move said rst movable element into firing position. l

2. In a fuse ci the type adapted to be fired by relative movement between the inner ends of a non-extensible cable and a surrounding sheath which are adapted to lie on or just beneath the surface of the ground, the sheath being so constructed and arranged as to elongate when deformed by the passage ,thereover of a tank or other heavy object, the outer ends of said cable and sheath being fixed relatively to one another, the combination of a fuse body, a member mounted in said fuse body to which the inner end of said cable is permanently secured, said member being incapable of outward movement relatively to said fuse body. a percussion cap ilxed in said fuse body, a striker member movably mounted in said fuse body, a spring operatively interposed between said fuse body and said striker member tending to move the latter into tiring contact with said percussion cap, yieldable means normally restraining said striker member from such movement under the influence of said spring, and a thrust element mounted in said fuse body for inward movement therein and normally having its inner end in abutment with the outer end of said striker member, the inner end of said cable 'sheath abutting against the outer end of said thrust element, whereby the inward movement of the inner end of said sheath upon elongation is transmitted by said thrust element to said striker member to overcome said yieldable restraining means and permit said spring to move said striker member into firing contact with said percussion cap.

3. A fuse according to claim 2 wherein the .member to which the inner end of said cable is of inter-threaded members surrounding said cable and abuttingl respectively said bead-like member andthe outer end of said sheath.

5. A ring mechanism according to claim 9 wherein said addusting means consists 0f a mem ber surrounding said cable with its outer end abutting said bead-like member and its inner end having threaded engagement with the outer end of said sheath.

6. A firing mechanism according to claim 9 wherein the outer end of said sheath consists of one of Vsaid elongation control devices, and wherein said adjusting means consists of a member surrounding said cable with its outer end abutting said bead-like member and its inner end having threaded engagement with the outermost lenticular element of the elongation control device forming the end of said sheath.

'7. A ring mechanism according to claim 9 wherein said adjusting means consists of a forked wedge member removably straddling said` cable with its wedge-forming surfaces abutting respectively said bead-like member and the outer end of said sheath.

8. In a tiring mechanism for explosive devices of the type comprising a non-extensible cable and a surrounding sheath which are adapted to lie on or just beneath the surface of the ground, the sheath being so constructed and arranged as to elongate'when deformed by the passage thereover of a tank or other heavy object, a plurality of elongation control devices interposed in said sheath at spaced points along its length, each consisting of a plurality of lenticular elements threaded on said cable of greater diameter than b with their outer surfaces lying beyond the peripheries of said elements, said rings being adapted to force said lenticular elements apart, and thereby to elongate the sheath, when crushed by the weight of an overpassing object.

9. A rlng mechanism for explosive devices oi the character described comprising a dexible,

i non-extensible cable, a iiexible sheath surroundy ing said cable and adapted to lie on or just beneath the surface of the ground, said sheath being so constructed and arranged as to elongate when deformed by the passage thereover of a tank or other heavy object and comprising a.

plurality of elongation control devices interposed therein at spaced points along its length, each of said devices consisting o -f a plurality .of lenticular elements threaded on said cable and of greater diameter than the remainder of said sheath, and rings of ductile metal surrounding and substantially spaced from said cable, said rings being interposed between and supported on the peripheral portions of the lenticular surfaces of adjacent elements with their outer surfaces lying beyond the peripheries of said elements, said rings being adapted to force said lenticular elements apart, and thereby to elongate the sheath, when crushed by the weight of an overpassing object, the inner ends of said cable and sheath being associated with the device to ybe exploded and the outer end of said cable extending beyond th corresponding end of said sheath and having a bead-like member secured thereto, and means of variable effective length in anaxial direction interposed between said beadlike member and the outer end of said sheath for adjusting the distance between the outer ends of d said cable and sheath.

GEORGES MARIE TELESPHORE ALEXANDRE FONTAINE. 

